diff --git a/src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md b/src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md
index b4ebd994c6..3aad6068f5 100644
--- a/src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md
+++ b/src/OpenTelemetry.Instrumentation.Runtime/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 * Change API for GC Heap Size for .NET 6 where the API has a bug
   ([#495](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/495))
+* Remove gc.heap.fragmentation.size metrics due to buggy API on .NET 6
+  ([#509](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/509))
 
 ## 1.0.0-rc.1
 
diff --git a/src/OpenTelemetry.Instrumentation.Runtime/README.md b/src/OpenTelemetry.Instrumentation.Runtime/README.md
index 8ecb0aa67f..c56c41df6b 100644
--- a/src/OpenTelemetry.Instrumentation.Runtime/README.md
+++ b/src/OpenTelemetry.Instrumentation.Runtime/README.md
@@ -103,6 +103,9 @@ Note: `ObservableGauge` should be changed to `ObservableUpDownCounter` once avai
 as `ObservableUpDownCounter` is the best fit of instrument type. The same applies
 to all the `ObservableGauge` below.
 
+Note: `gc.heap.fragmentation.size` metrics is removed for .NET 6 because of a
+[bug](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/issues/496).
+
 The APIs used to retrieve the values are:
 
 * [GCMemoryInfo.TotalCommittedBytes](https://docs.microsoft.com/dotnet/api/system.gcmemoryinfo.totalcommittedbytes):
diff --git a/src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs b/src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs
index a43d572d6d..552e2b1b87 100644
--- a/src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs
+++ b/src/OpenTelemetry.Instrumentation.Runtime/RuntimeMetrics.cs
@@ -121,7 +121,10 @@ static RuntimeMetrics()
                     unit: "bytes",
                     description: "The heap size (including fragmentation), as observed during the latest garbage collection. The value will be unavailable until at least one garbage collection has occurred.");
             }
+#endif
 
+#if NET7_0_OR_GREATER
+            // TODO: Not valid until .NET 7 where the bug is fixed. See context in https://github.com/open-telemetry/opentelemetry-dotnet-contrib/issues/496
             // TODO: change to ObservableUpDownCounter
             MeterInstance.CreateObservableGauge(
                 $"{metricPrefix}gc.heap.fragmentation.size",